The Pinwheel is one of the more difficult galaxies to image at 21 million light years distance. Like the Milky Way M101 has several bright red hydrogen alpha rich areas similar to our own Lagoon Nebula. These collections of dust and gases are typically areas of new star formation and glow due to the radiation of the young stars within them. If you look closely you can also spot at least twenty other small galaxies in the image including the edge on galaxy NGC5422 at 87 million light years distance (lower right) and the spiral galaxy NGC5474 (upper left).